Trait Widget

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pub trait Widget:
    Brick
    + Send
    + Sync {
Show 13 methods    // Required methods
    fn type_id(&self) -> TypeId;
    fn measure(&self, constraints: Constraints) -> Size;
    fn layout(&mut self, bounds: Rect) -> LayoutResult;
    fn paint(&self, canvas: &mut dyn Canvas);
    fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>;
    fn children(&self) -> &[Box<dyn Widget>];
    fn children_mut(&mut self) -> &mut [Box<dyn Widget>];

    // Provided methods
    fn is_interactive(&self) -> bool { ... }
    fn is_focusable(&self) -> bool { ... }
    fn accessible_name(&self) -> Option<&str> { ... }
    fn accessible_role(&self) -> AccessibleRole { ... }
    fn test_id(&self) -> Option<&str> { ... }
    fn bounds(&self) -> Rect { ... }
}

Expand description

Core widget trait that all UI elements implement.

§Brick Architecture (PROBAR-SPEC-009)

Widget REQUIRES the Brick trait, enforcing the “tests define interface” philosophy:

Every Widget has assertions that define its contract
Every Widget has a performance budget
Rendering is blocked if assertions fail (Popperian falsification)

§Lifecycle

verify: Check Brick assertions (mandatory)
measure: Compute intrinsic size given constraints
layout: Position self and children within allocated bounds
paint: Generate draw commands (only if can_render() returns true)

Required Methods§

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fn type_id(&self) -> TypeId

Get the type identifier for this widget type.

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fn measure(&self, constraints: Constraints) -> Size

Compute intrinsic size constraints.

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fn layout(&mut self, bounds: Rect) -> LayoutResult

Position children within allocated bounds.

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fn paint(&self, canvas: &mut dyn Canvas)

Generate draw commands for rendering.

§Panics

Panics if called when can_render() returns false (Brick verification failed).

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fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

Handle input events.

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fn children(&self) -> &[Box<dyn Widget>]

Get child widgets for tree traversal.

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fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

Get mutable child widgets.

Provided Methods§

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fn is_interactive(&self) -> bool

Check if this widget is interactive (can receive focus/events).

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fn is_focusable(&self) -> bool

Check if this widget can receive keyboard focus.

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fn accessible_name(&self) -> Option<&str>

Get the accessible name for screen readers.

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fn accessible_role(&self) -> AccessibleRole

Get the accessible role.

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fn test_id(&self) -> Option<&str>

Get the test ID for this widget (if any).

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fn bounds(&self) -> Rect

Get the current bounds of this widget.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types§

Source §

Trait Widget Copy item path

§Brick Architecture (PROBAR-SPEC-009)

§Lifecycle

Required Methods§

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

§Panics

fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

Provided Methods§

fn is_interactive(&self) -> bool

fn is_focusable(&self) -> bool

fn accessible_name(&self) -> Option<&str>

fn accessible_role(&self) -> AccessibleRole

fn test_id(&self) -> Option<&str>

fn bounds(&self) -> Rect

Dyn Compatibility§

Implementations on Foreign Types§

impl Widget for Button

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

fn is_interactive(&self) -> bool

fn is_focusable(&self) -> bool

fn accessible_name(&self) -> Option<&str>

fn accessible_role(&self) -> AccessibleRole

fn test_id(&self) -> Option<&str>

impl Widget for Chart

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

fn event(&mut self, _event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

fn is_interactive(&self) -> bool

fn is_focusable(&self) -> bool

fn accessible_name(&self) -> Option<&str>

fn accessible_role(&self) -> AccessibleRole

fn test_id(&self) -> Option<&str>

impl Widget for Checkbox

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

fn is_interactive(&self) -> bool

fn is_focusable(&self) -> bool

fn accessible_name(&self) -> Option<&str>

fn accessible_role(&self) -> AccessibleRole

fn test_id(&self) -> Option<&str>

impl Widget for Column

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

fn test_id(&self) -> Option<&str>

impl Widget for Container

fn type_id(&self) -> TypeId

fn measure(&self, constraints: Constraints) -> Size

fn layout(&mut self, bounds: Rect) -> LayoutResult

fn paint(&self, canvas: &mut dyn Canvas)

fn event(&mut self, event: &Event) -> Option<Box<dyn Any + Send>>

fn children(&self) -> &[Box<dyn Widget>]

fn children_mut(&mut self) -> &mut [Box<dyn Widget>]

fn test_id(&self) -> Option<&str>

impl Widget for DataCard

fn type_id(&self) -> TypeId

Trait Widget